Atomizer assembly for use in flame photometers



Aug. 8, 1950 ATOMIZER ASSEMBLY FOR USE IN A FLAME PHOTOMETER R. L. HOOD 2,517,666

Filed June 12, 1947.

. INVENTOR P056??? 4.. H000,

3/ .C kauggwn BY Nome-(d ATTORNEY Patented Aug. 8, 1950 ATOMIZER ASSEMBLY FOR USE IN FLAME PHOTOMETERS Robert L. Hood, Stamford, Conn assignor to American 'Cyanamid Company, New York,N. .Y., a corporation of Maine Application June 12, 1947, Serial No. 754,175

(cuss-24) 3Claims. 1

This invention relates to an atomizer assembly which is especially adapted for use in a flame photometer.

A flame photometer is a device which is used to determine the concentration of substances, more particularly alkali and alkaline-earth metals, in liquids. Briefly described, the procedure involved generally consists in atomizing an aqueous solution containing the metal to be analyzed and conducting the resulting vapor or mist into the base of a gas burner, whereupon the vapor is carried into the flame and ignited. The light arising from the flame characteristic of the element being determined is filtered free of other radiation and is brought to fall upon a photocell. By measuring the intensity of the light produced with solutions of known concentration and preparing a calibration curve of intensity versus concentration, the metal content of other solutions may subsequently be determined by making use of the curve.

An apparatus and method whereby the concentration of alkali and alkaline-earth metals may be quantitatively determined are disclosed and claimed in the copending application of John W. Berry, Serial No. 701,562, filed October 5, 1916 (now abandoned). The present invention is concerned specifically with the atomizer assembly disclosed but not separately claimed in the aforementioned Berry application.

It is an object of the present invention to provide a novel andimproved atomizer assembly which is especially adapted for use in a flame photometer, which .is relatively simple in design and which is adapted for mass production at a relatively low cost.

Another object of the invention. is to provide an atomizer assembly, and particularly the atomizer chamber thereof, which permits better visibility during operation than those heretofore employed and which alsoiseasierto use thanthe prior devices.

Another object of the inventionis to provide-an atomizer assembly utilizing glass parts in which a minimum of glass blowing or shaping is neces sary and wherein the glass parts are removable for cleaning or replacement.

Another object of the invention is to provide a compactly designed atomizer assembly which can be retracted from the remainder of the flame photometer apparatus of which it is a part, so that the atomizer assembly including the atomization chamber thereof will be visible during operation of the photometer.

Other objects-of the invention will be apparent to those skilled in-the art from the accompany- .ing drawing and the description which follows.

The novel features of my invention are set forth in the appendedclaims. The invention itself, however, will best be understood by reference to the following more detailed description when considered in connection with the accompanying drawing in which Fig. 1 is a perspective view of an atomizer assembly embodying my. invention and illustrative thereof; and'Fig.2 is a side view, partly in section, of the atomizer assembly shown in Fig. .1.

Referring to the drawing, the atomizer assembly l is mounted on thepanel board 2 of the flame photometer by means of rods 3 which pass through openings 4 in the panelboard. The rods 3 are preferably made of metal and fit closely but slidably in the openings 4 so that the assembly -I can be slid in and out of the panel board through opening 5 for watching the atomization during operation of the flame photometer or for cleaning or replacement of parts.

The atomizer-assembly comprisesan atomizer 6 to which compressed air is introduced through conduit 1. The aqueous solution containing the substance to be analyzed is introduced into the funnel 8 which connects with the fluid inlet 9 of the atomizer 6. The atomizer is adjusted by means of needle valve H1. The atomizer nozzle H is positioned on anend closure member such as the disc l2 so that the said nozzle is in communication with the opening l3in the said disc. The atomizer is held firmly in position on disc I2 by suitable means, e. g., by means of bracket M which preferably is bolted to the disc.

A glass cylinder I5 is providedwith end closure members thereby to form a chamber adapted to receive a mistor vapor of the aqueous solution containing the substance tobe analyzed. For example, the said cylinder may be aflixed tightly to end plates such as discs l2 and I6 by means of bolts I! to form said chamber. Suitable gasket materialmay be interposed between the ends of the cylinder I5 and the discs l2 and It in order to form a tighter seal therebetween. Discs l 2 and I6 are preferably made of metal, e. g., stainless steel.

A conduit l8 passes through an opening. {9 in the disc l6 and projects a substantial distance into the cylinder 15. This conduit serves for conducting the mist formed within the cylinder l5 and, after connecting with a flexible tubing,.for the passage of the same to a gas burner (not shown). The conduit 18 and the nozzle ll of the atomizer 6 advantageously are in approximately 3 the same plane and, also, advantageously may be positioned, as shown, so that they are in substantial alignment with the axis of the cylinder l5. The conduit 18 may be threaded as indicated at 20 and held tightly to the disc 16 by means of nut 2| and flange 22.

A bafiie 23 is interposed between the open end of the conduit I8 and the stream of mist injected into the cylinder l through the atomizer nozzle ll. Preferably the bafiie 23 is made of glass and envelops a substantial part of the conduit 1 B that extends into the cylinder l5. This baffle is spaced from the disc l6 so as to provide an opening 24 therebetween. The baffle 23 is open at the end nearest the disc it and is closed at the opposite end. Advantageously it is tubular in shape and rounded at the closed end as shown. A baiile such as shown also functions as a trap to sepa rate large particles of liquid from the mist and prevents their entrance into the open end of the conduit It. In this way a substantially homogeneous mist comprising finely divided particles of liquid suspended in air enters the conduit 48. In

other words, the baflie 23 separates the larger particles from the finer particles of mist and the conduit I 8 then conducts these finer particles into the photometer.

The bafile 23 is held in position by any suitable means. One means is by use of the clamps 25 which engage the beaded edge 25 of the bafiie as shown. The clamps are affixed to a suitable base member which is secured in position against the disc 16 by means of the flange '22 and the nut 2 I.

The conduit l8 advantageously is provided with a dam 2'! which prevents condensate (that is,"

liquid which is formed as the result of the separation of the larger particles from the finer particles of mist) from running along the exterior surfaces thereof and thence to the opening of the conduit l8.

The liquid formed in the cylinder l5 by the separated larger particles is withdrawn through the outlet 28 in the bottom wall of the cylinder. This outlet may be connected by means of a flexible tubing 29 to a trap (not shown), which latter in turn may be connected to a drain by another length of flexible tubing.

The conduit 1 through which compressed air is introduced to the atomizer i3 advantageously is arranged so as to pass through an opening 39 in the disc l2, being then connected by a flexible tubing 3! to 9, suitable source of compressed air.

As mentioned hereinbefore the atomizer assembly is adapted to slide in and out from the panel board 2. When the flame photometer is in operation, the atomizer assembly is pulled out so that the atomization may be observed, whereas When the photometer is not in operation or is being transported from place to place, the atomizer unit is pushed into the instrument in order to protect it from breakage.

It will be understood, of course, that means other than the funnel 8 may be employed for supplying the aqueous solution containing the substance to be analyzed to the atomizer 6. Thus, the atomizer could be connected by a conduit to a supply reservoir containing the solution, and by the use of suitable valves could be fed to the atomizer at any desired rate.

In the operation of the atomizer assembly of my invention a solution containing the substance to be analyzed and compressed air are charged to the atomizer 6, the proportions thereof being adjusted by the needle valve H3. The solution is atomized and forced through the atomizer nozzle ll into the chamber formed by the glass cylinder l5 and the discs l2 and I6 to which the said cylinder is tightly affixed. The atomized solution is in the form of a mist or vapor, that is, the solution in finely divided state is dispersed or suspended in the stream of air flowing to the chamber. Some condensation occurs, and the condensate is withdrawn through the drain outlet 28. By reason of the particular construction embraced by my invention, a maximum amount of a substantially homogeneous dispersion of fine particles of liquid passes through the conduit I8, after which it is mixed with a com bustible gas adapted to give a low-temperature flame, e. g., ordinary illuminating gases such as the various types of city gas in common use, propane, butane, etc.

Reference is made to the aforementioned Berry application Serial No. 701,562 for a more detailed description of the operation of a flame photometer in which is utilized at atomizer assembly of the kind hereinbefore described.

From the foregoing description when considered in connection with the accompanying drawing it will be seen that the present invention provides an atomizer assembly which is especially adapted for use in a flame photometer and which has the advantages over prior constructions of being easy to clean and use and which is visible to the eye, due to the fact that the cylinder i5 is a transparent structure, during operation of the device. It is sturdy, compact, relatively inexpensive, and lends itself readily to mass production methods. Furthermore, parts requiring replacement or cleaning can be removed without difficulty.

I claim:

1. An atomizer assembly adapted for use in a flame photometer comprising means for supplyin to an atomizer an aqueous solution containing the substance to be analyzed, a transparent structure provided with end closure members thereby to form a chamber adapted to receive a mist of said solution, means including an atomizer for atomizing said solution through an opening in one of said closure members to form a mist thereof within said chamber, said mist containing both large and fine particles of liquid, means for withdrawing liquid formed of the larger particles which separate from the said mist from the bottom of said chamber, a conduit for conducting the mist substantially free from the larger particles of liquid from the said chamber, said conduit extending a substantial distance into the said chamber and passing through the end closure member opposite the one through which said solution is atomized, a baffle enveloping a substantial part of the said conduit that extends into the said chamber, said baflie being spaced from the end closure member through which said conduit projects, being open at the end nearest said closure member and being closed at the opposite end, and means for holding said baflie in position, said baffle separating the larger particles from the finer particles of mist and said conduit conducting said finer particles into the photometer.

2. An atomizer assembly adapted for use in a flame photometer comprising a glass cylinder, a plate closing one end of said cylinder, an atomizer mounted on said plate, the nozzle of the atomizer projecting through an opening in the said plate, means for supplying to the atomizer an aqueous solution containing the substance to be analyzed, means for supplying air to the atomizer, a second plate closing the other end of the said cylinder, means for connecting the said plates to each other and for holding the said cylinder tightly against the said plates thereby forming a chamber adapted to receive the mist produced when the said solution is atomized, said mist containing both large and fine particles of liquid, means for withdrawing liquid formed of the larger particles which separate from the said mist from the bottom of said chamber, a conduit for conducting the mist substantially free from the larger particles of liquid from the said chamber, said conduit passing through an opening in the second plate and extending a substantial distance into the said chamber, a glass baffle enveloping a substantial part of the said conduit that extends into the said chamber, said bafile being spaced from the second plate, being open at the end nearest said plate and being closed at the opposite end, and means for holding said baiile in position, said baflie separating the larger particles from the finer particles of mist and said conduit conducting said finer particles into the photometer.

3. In a flame photometer, an atomizer assem bly comprising a horizontal glass cylinder, a metal disc closing one end of said cylinder, an atomizer rigidly mounted on said disc, the nozzle of the atomizer passing through an opening in the said disc, means for supplying to the atomizer an aqueous solution containing the substance to be analyzed, means for supplying air to the atomizer, a second metal disc closing the other end of the said cylinder, means for connecting the said discs to each other and for holding the said cylinder tightly against the said discs thereby forming a chamber adapted to receive the mist produced by atomization of the said solution, said mist containing both large and fine particles of liquid, means for Withdrawing liquid formed of the larger particles which separate from the said mist from the bottom of said chamber, a conduit for conducting the mist substantially free from the larger particles of liquid from the said chamber, said conduit passing through an opening in the second metal disc and extending a substantial. distance into the said chamber, the said conduit and nozzle being in substantial alignment with the axis of the said cylinder, a dam on said conduit Within said chamber, a glass tubular baflle enveloping a substantial part of the said conduit, said baille being spaced from the second metal disc so as to provide an opening therebetween for the passage of mist to the said conduit and being open at the end nearest said disc and closed and rounded at the opposite end, said conduit being centrally positioned Within said bailie, means for clamping said bafile in position, said baffle separating the larger particles from the finer particles of mist and said conduit conducting said finer particles into the photometer, and means for slidably retractin the said atomizer assembly from the flame photometer of which it is a part so that the said assembly will be visible during operation of the photometer.

ROBERT L. HOOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,430,066 Evans Sept. 26, 1922 1,534,831 Berg Apr. 21, 1925 1,911,130 Hannigan May 23, 1933 2,020,850 Myhren et al Nov. 12, 1935 2,072,375 McCallum Mar. 2, 1937 2,097,650 Stampe Nov. 2, 1937 2,129,490 Buchs Sept. 6, 1938 FOREIGN PATENTS Number Country Date 16,730 Great Britain Aug. 2, 1890 237,992 Great Britain Aug. 7, 1925 417,631 Great Britain Aug. 22, 1929 

